The Department of Chemistry at Princeton University will purchase an Electron Paramagnetic Resonance/Electron-Nuclear Double Resonance Spectrometer with support from the BRS Shared Instrumentation Program. The instrument is needed by members of the Chemistry and Biology Departments for NIH funded research in the following areas: 1. Protein Control of Proton and Electron Transfer 2. Molecular Probes of the Mechanism of Cytochrome P450 3. Cytoskeleton Membrane Interactions 4. Mechanistic Studies of alpha-Ketoacid Dioxygenasese 5. Stabilized Prostacyclins to Treat Vascular Diseases 6. Synthesis of Natural Anticancer Agents 7. Natural Product Synthesis 8. Metal Centers in Biology: Hemes, Iron-Sulfur and Copper Proteins 9. Hemeprotein Structure and Dynamics The proposed EPR spectrometer is needed to replace an aging spectrometer that was purchased in 1968 and is now out of date and partially non-functional. The ENDOR accessory will expand the capabilities of the user group into a new area by permitting high resolution studies of paramagnetic materials. This will be especially valuable for studies of the chemical structure and dynamics of distant nuclei and magnetically anisotropic materials. Through these research studies this instrument will be used in training the next generation of Princeton students entering biomedical fields.